NSF PRFB FY 2023: Impact of Environment-Seagrass-Microbe Interactions on Seagrass Stress Response and Ecosystem Functions

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Beneficial bacteria can reduce the impact of stressful conditions on plants. Seagrasses are marine plants that grow in stressful environments. One common stressor is high sulfide concentrations. Sulfide is a toxic chemical that is abundant in marine sediments and can cause seagrass die-offs. The bacteria, Candidatus Thiodiazotropha, can detoxify seagrass sediments by oxidizing sulfide, which is a process that removes sulfide from the environment. This research will determine how the presence and abundance of Ca. Thiodiazotropha impacts seagrass health under various levels of environmental stress. Seagrass meadows are an economically and culturally valuable resource, and positive interactions between seagrasses and bacteria provide a potential tool for evaluating seagrass vulnerability to stressors and increasing stress tolerance of restored seagrasses. This research will integrate environment-seagrass-microbe interactions to better understand the generality and magnitude of plant-microbe interactions under varying environmental conditions. The fellow will analyze (a) the relative impacts of plant traits vs. environmental conditions on Ca. Thiodiazotropha abundance using a reciprocal transplant experiment, (b) how interactions between sulfide stress and Ca. Thiodiazotropha affect seagrass performance using a mesocosm experiment, and (c) how seagrass-microbe interactions translate environmental heterogeneity to higher-order variation in plant performance and nutrient cycling using an incubation experiment. Results from this research will advance fundamental knowledge related to the evolutionary ecology of plant microbiomes, drivers of nitrogen cycling in coastal ecosystems, and the impact of environment-plant-microbe interactions on ecosystem functions and processes. The fellow will receive training in microbial ecology and biogeochemistry techniques, inclusive pedagogical strategies, and science communication. This project will promote the training of students, including students from groups underrepresented in the sciences, through the development and implementation of high school science curriculum and mentorship of undergraduate students. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.